#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
	int n;
	while(scanf("%d",&n)!=EOF)
	{
		int m,ans;
		ans = n/5;
		m = n%5;
		if(m) ans++;
		printf("%d\n",ans);
	}
}
